Abstract:recent years, although this procedure usually implies extra manufacturing operations and costs. On the other hand, sintered materials contain themselves surface cavities that could potentially act as surface texture and, consequently, lead to friction reduction. This research aims to extend the current knowledge on the tribological influence of micro surface irregularities (pores and laser texture) under lubricated experimental tests and explore the use of these features for tribological applications. Samples … Show more
“…Besides, an ad-hoc measuring and postprocessing procedure, including the choice of the roughness filter and cut-off values), was developed to weakening pore contours' effects on roughness characterization. More details of this procedure can be found in previous publications [29,[56][57][58]. The surface roughness of the reference smooth material NP was evaluated using the Sq parameter.…”
Section: Powder Metallurgy Sintering Techniques and Porositymentioning
confidence: 99%
“…Different sintering parameters were used for varying porosity, see Table 1. Only one sintering condition is presented for the ball-shaped samples as this set of parameters (Ball-Sint) was the only one where open surface pores could be observed after machining [29,56]. Three different compacting pressures were used with the conventional sintering technique for obtaining disc samples with different porosity.…”
Section: Powder Metallurgy Sintering Techniques and Porositymentioning
This work critically scrutinizes and compares the tribological performance of randomly distributed surface pores in sintered materials and precisely tailored laser textures produced by different laser surface texturing techniques. The pore distributions and dimensions were modified by changing the sintering parameters, while the topological features of the laser textures were varied by changing the laser sources and structuring parameters. Ball-on-disc tribological experiments were carried out under lubricated combined sliding-rolling conditions. Film thickness was measured in-situ through a specific interferometry technique developed for the study of rough surfaces. Furthermore, a machine learning approach based on the radial basis function method was proposed to predict the frictional behavior of contact interfaces with surface irregularities. The main results show that both sintered and laser textured materials can reduce friction compared to the untextured material under certain operating conditions. Moreover, the machine learning model was shown to predict results with satisfactory accuracy. It was also found that the performance of sintered materials could lead to similar improvements as achieved by textured surfaces, even if surface pores are randomly distributed and not precisely controlled.
“…Besides, an ad-hoc measuring and postprocessing procedure, including the choice of the roughness filter and cut-off values), was developed to weakening pore contours' effects on roughness characterization. More details of this procedure can be found in previous publications [29,[56][57][58]. The surface roughness of the reference smooth material NP was evaluated using the Sq parameter.…”
Section: Powder Metallurgy Sintering Techniques and Porositymentioning
confidence: 99%
“…Different sintering parameters were used for varying porosity, see Table 1. Only one sintering condition is presented for the ball-shaped samples as this set of parameters (Ball-Sint) was the only one where open surface pores could be observed after machining [29,56]. Three different compacting pressures were used with the conventional sintering technique for obtaining disc samples with different porosity.…”
Section: Powder Metallurgy Sintering Techniques and Porositymentioning
This work critically scrutinizes and compares the tribological performance of randomly distributed surface pores in sintered materials and precisely tailored laser textures produced by different laser surface texturing techniques. The pore distributions and dimensions were modified by changing the sintering parameters, while the topological features of the laser textures were varied by changing the laser sources and structuring parameters. Ball-on-disc tribological experiments were carried out under lubricated combined sliding-rolling conditions. Film thickness was measured in-situ through a specific interferometry technique developed for the study of rough surfaces. Furthermore, a machine learning approach based on the radial basis function method was proposed to predict the frictional behavior of contact interfaces with surface irregularities. The main results show that both sintered and laser textured materials can reduce friction compared to the untextured material under certain operating conditions. Moreover, the machine learning model was shown to predict results with satisfactory accuracy. It was also found that the performance of sintered materials could lead to similar improvements as achieved by textured surfaces, even if surface pores are randomly distributed and not precisely controlled.
“…A vast variation in particle size was studied by Sasada et al [56]. These authors measured the wear caused by SiC particles range from 3 up to 150 μm under threebody configuration, constantly testing similar body and counter-body material.…”
Section: Description Of Abrasion Severitymentioning
He was one of the primary organizers of TriboBR conferences, the International Brazilian Conference on Tribology. His research activities are well correlated to industry demands, especially in line with the automotive sector. He belongs to an Excellence Research Nucleus of plasma-assisted processes to reduce wear and corrosion, bringing his experience as a visiting researcher at the University of Birmingham, England. He is a recognized researcher by CNPq -The Brazilian National Council for Scientific and Technological Development. He is a subeditor of Matéria and served as a guest editor for SN Applied Sciences and Industrial Lubrication Tribology.
“…Principal parameters of size (area) and shape (circularity index) were considered for the characterisation of surface pores [41]. Mechanical properties of sintered materials (elastic modulus 𝐸 and Poisson's ratio 𝜈) were estimated based on material total porosity, as previously done in [29,32,42,43].…”
Section: Specimen Characterisationmentioning
confidence: 99%
“…The manufacturing processes (grinding) led surface pores to open and, consequently, more porous discs (D4) showed higher roughness values than less porous ones (D5 and D6), see Table 3. Notice that 𝐸 and 𝜈 are 70 GPa and 0.22, respectively, for the glass disc used in the film thickness measurements [43,50].…”
Section: Porosity and Microstructural Characteristics Of Sintered Specimensmentioning
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